贵州喀斯特地区土壤细菌群落结构特征及变化

为探明贵州喀斯特不同植被演替群落下的土壤细菌群落结构及变化特征,本文利用高通量测序技术对5个主要植被演替群落(稀灌草丛、藤刺灌丛、灌木林、乔灌过渡林、乔木林)的根际(竹叶椒)、非根际土壤细菌群落结构及环境因子进行了分析研究。结果表明:贵州喀斯特高原土壤细菌类群主要为变形菌门(Proteobacteria)、酸杆菌门(Acidobacteria)、疣微菌门(Verrucomicrobia)、放线菌门(Actinobacteria)、厚壁菌门(Firmicutes)、拟杆菌门(Bacteroidetes)和浮霉菌门(Planctomycetes),其相对丰富度分别为43.35%、12.97%、7.53%、7.12%、6.19%、5.35%、5.05%,未分类类群占7.36%。样品中检测到了较低丰度的广古菌门和泉古菌门。随植被群落演替,根际土壤中变形菌门、厚壁菌门和浮霉菌门丰度逐渐增加;非根际土壤中酸杆菌门和疣微菌门丰度随植被演替逐渐减小。贵州喀斯特高原土壤细菌的影响因子大小为土壤有机碳、土壤总氮、含水量、电导率等,其中土壤有机碳和土壤总氮有显著性影响。

Compositional Characteristics and Variations of Soil Microbial Community in Karst Area of Puding County, Guizhou Province, China

By using high-throughput pyrosequencing technique, this paper investigated the soil microbial abundances and community structure in 5 succession stages (sparse-shrub tussock, thorny shrub, shrub, shrub-tree transitional forest, and secondary forest) in the Puding karst area, central of Guizhou Province, China, and analyzed the main environmental factors affecting these changes. Results showed that in all the soil samples, procaryote microbial was dominated with Proteobacteria(43.35%), Acidobacteria(12.97%), Verrucomicrobia(7.53%), Actinobacteria(7.12%), Firmicutes(6.19%), Bacteroidetes(5.35%), and Planctomycetes(5.05%), while unclassified was 20.65%. The few low abundance of Euryarchaeota and Crenarchaeotawere detected in the karst area soil. in Zanthoxylum planispinum rhizosphere soil, the abundance of Proteobacteria, Firmicutes and Planctomycete gradually increased with the vegetation succession. However, in the non-rhizosphere soil, the abundance of Acidobacteria and Verrucomicrobia decreased from 14.74% to 12.92% and 11.29% to 6.11%, respectively. It was figured out that TOC, TN, soil water content, EC, available phosphorus content, pH and exchangeable calcium content were key factors affecting the microbial community in the karst soil, and TOC and TN were significantly different.